This study will focus on optimizing basophil numbers and purity. We will then characterize the time-course and antigen concentration-dependence of four functional responses to FceR1 corsslinking: degranulation, membrand and cytosketal responses, VLA-4 activation, and the synthesis of IL-4. During these exploratory studies, special attention will be paid to variability between donors in FceR1 density and responses to crosslinking.